When loading or reloading product display trays of the type referred to above, the spring-loaded pusher paddle must be held in a retracted position while new product items are loaded into the tray. To enable store personnel to have both hands available for loading of product, it is typical to provide a means for mechanically locking the paddle in a fully retracted position while the loading operations are taking place. A variety of arrangements and mechanisms have been proposed for accomplishing this. One such mechanism is reflected in British patent publication 2290077, in which a vertically movable latch element is mounted on the back of a spring-urged pusher paddle. When the paddle is moved to a retracted position, the latch is depressed so that it engages the track and retains the paddle in position while products are loaded into the tray. When the tray is fully loaded, a push against the paddle in a backward direction releases the latch, which returns to an elevated position allowing the paddle to move forwardly to advance the product column.
European patent EP 0986980 illustrates a basic arrangement in which the base portion of a pusher paddle is provided with a hook engageable with a recess provided in the back portion of the track. When the paddle is retracted for loading of the tray, the entire paddle is tilted backwards to press the hook into the recess and the lock the paddle. The paddle is later released by pressing it backward and tilting it forward to release the hook.
U.S. Pat. No. 7,931,156 illustrates an arrangement similar to that of the British publication 2 290 077 in that a vertically movable latch element is mounted to the back of the pusher paddle. The latch can be depressed when the paddle is in a retracted position, in order to lock the paddle during reloading operations. When reloading is completed, the paddle is pressed rearwardly (either manually or as a result of being pressed backward after becoming fully loaded with packages) causing release of a latch spring and thus allowing the tray to move forwardly under the action of the paddle spring.
US patent publication 2012/0211450, owned by the assignee of this application, Trion Industries, Inc., illustrates an arrangement in which a locking element is positioned against the back face of a flexible and tiltable pusher paddle. During normal operations, the paddle is in an upright position, in which the locking element is ineffective. For reloading operations, the paddle is pushed to the back of the tray, and its geometry is such that it tilts forwardly when in its rearward or reload position. In a forwardly tilted position of the paddle, the locking element grips guide rods forming the base of the tray and retains the paddle in a retracted position. When the paddle is tilted back to an upright position, either manually or by the loading of a final product package into a substantially full tray, the lock automatically releases and allows the paddle to move forwardly under the action of its spring.
US patent publication 2013/0112634 discloses a mechanism in which a U-shaped locking element is inserted through slots in the face of the pusher and has locking elements extending to the rear that automatically engage the tray and lock the pusher when the pusher is moved to a retracted position. Rearward pressure on a portion of the locking element exposed in front of the pusher releases the locking elements and allows the paddle to be pushed forwardly by its spring. This arrangement has the disadvantage of automatically locking the paddle in a retracted position anytime it is moved to the rear of the base. When this happens without the store clerk noticing, the paddle may remain in its locked, retracted position and not function to push the product column to the front as intended.
All of the above devices function at some level to allow a spring operated pusher paddle to be locked in a retracted position for reloading operations. However, all of them suffer from certain shortcomings, either from an operating standpoint or from extra cost and complication in the manufacture.